From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5A24C63797 for ; Thu, 22 Jul 2021 13:26:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5B45060FE7 for ; Thu, 22 Jul 2021 13:26:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B45060FE7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D9B1C6B0033; Thu, 22 Jul 2021 09:26:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D4C106B005D; Thu, 22 Jul 2021 09:26:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C39626B006C; Thu, 22 Jul 2021 09:26:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0145.hostedemail.com [216.40.44.145]) by kanga.kvack.org (Postfix) with ESMTP id ACB466B0033 for ; Thu, 22 Jul 2021 09:26:56 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 4EB751B3EF for ; Thu, 22 Jul 2021 13:26:56 +0000 (UTC) X-FDA: 78390299232.29.0A32AB1 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf17.hostedemail.com (Postfix) with ESMTP id 06848F0003B9 for ; Thu, 22 Jul 2021 13:26:55 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 709F360FEE; Thu, 22 Jul 2021 13:26:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626960415; bh=+uL4L29wsoeIrn9I4PopKZ7ciOxU0fozSHm7hEtJRaA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mOzAXRtqcugR4cbq3OZ5I8AKQ8QQhGkkyOozUUY9xBQ0I5NEwtkdgEsSwZCJsdN/+ 3bjvn18Caqjm7YHAFh8jWTESB+wOgqiuj5PRefDbB42xcQurO6032HAthHLzg3O2Hd 5NQaMgvg+iMGAQSuZ7xMqrR8uynVN49YlEvWISUc= Date: Thu, 22 Jul 2021 15:26:52 +0200 From: Greg KH To: Matthew Wilcox Cc: Zhouyi Zhou , Chris Clayton , Oleksandr Natalenko , Miaohe Lin , Boqun Feng , paulmck@kernel.org, linux-kernel , stable@vger.kernel.org, Chris Rankin , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , rcu , Andrew Morton , Linux-MM , "Huang, Ying" Subject: Re: linux-5.13.2: warning from kernel/rcu/tree_plugin.h:359 Message-ID: References: <5812280.fcLxn8YiTP@natalenko.name> <2237123.PRLUojbHBq@natalenko.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=mOzAXRtq; spf=pass (imf17.hostedemail.com: domain of gregkh@linuxfoundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org X-Stat-Signature: cf9ro17nmh4za5r9uthwx8ncq9dnambu X-Rspamd-Queue-Id: 06848F0003B9 X-Rspamd-Server: rspam01 X-HE-Tag: 1626960415-431274 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jul 22, 2021 at 01:36:02PM +0100, Matthew Wilcox wrote: > On Thu, Jul 22, 2021 at 04:57:57PM +0800, Zhouyi Zhou wrote: > > Thanks for reviewing, > > > > What I have deduced from the dmesg is: > > In function do_swap_page, > > after invoking > > 3385 si = get_swap_device(entry); /* rcu_read_lock */ > > and before > > 3561 out: > > 3562 if (si) > > 3563 put_swap_device(si); > > The thread got scheduled out in > > 3454 locked = lock_page_or_retry(page, vma->vm_mm, vmf->flags); > > > > I am only familiar with Linux RCU subsystem, hope mm people can solve our > > confusions. > > I don't understamd why you're still talking. The problem is understood. > You need to revert the unnecessary backport of 2799e77529c2 and > 2efa33fc7f6e Sorry for the delay, will go do so in a minute... greg k-h